The present invention relates to an apparatus for removing organic substances from a substrate, which is used for removing organic contaminants stuck on the surface of a substrate; removing, before etching, any resist remaining at resist pattern openings after development, or removing, after etching, any photoresist remaining on the surface of a substrate, by the use of ozone and irradiation with ultraviolet rays. These are required when semiconductor substrates, substrates for photomasks or substrates for liquid crystal displays (hereinafter referred to as "substrates") are coated with photoresists for carrying out photo-etching.
In producing semiconductors, in order to remove organic substances stuck on the surface of substrates or unnecessary resists remaining after development processing, cleaning of the surface of the substrates is performed by feeding ozone to the substrate while being radiated with ultraviolet rays, thereby decomposing the organic substances by cooperative action of ultraviolet rays and ozone.
In Japanese unexamined patent publication No. 193030/1984 , entitled "Treatment apparatus", a dry washing apparatus is disclosed in which oxygen gas is fed to a treatment chamber internally provided with an ultraviolet source to generate ozone therein, and a substrate to be treated is introduced into the treatment chamber. According to this prior art apparatus, the substrate being treated is placed on a reciprocating transport section and conveyed into or out of the treatment chamber. Oxygen gas is blown along the surface of the substrate in one direction. This apparatus is characterized by the transport section which is designed to support a substrate at only its peripheral edge portion so that the face and back of the substrate may be open.
In the above prior art apparatus, there is concern that the treatment effect of the gas to the surface of the substrate is different between the part of the substrate near to a gas outlet and the part distant therefrom, resulting in the non-uniformity of treatment. This difference is due to having the arrangement in which the oxygen gas used for the dry washing is blown off along the surface of the substrate in one direction.
In the prior art means, there is another problem. Since the amount of ozone to be formed by ultraviolet rays is small, the ability to decompose and remove organic contaminants stuck on the substrate is poor and the treatment requires a longer time accordingly.